polymerase chain reaction

• DNA polymerase synthesizes DNA in a 5' to 3' direction by building new strands complementary to existing DNA strands.
• Genetic Engineering and Recombinant DNA Technology are topics covered in the Science & Research Cluster course titled "Genetic Engineering and Recombinant DNA Technology" for the 2023-2024 school year.
• Genetic Engineering allows scientists to modify genomes of a variety of organisms, from bacteria to plants and animals, to either improve the characteristics of the organism or make biotechnology products.
• Genetically Modified Organism (GMO) refers to an organism whose genome has been modified in some way, usually by using recombinant DNA technology.
• Transgenic Organism is an example of a GMO that has had a gene from another species inserted into its genome.
• DNA replication allows living organisms to pass on the code for making proteins from one generation to the next.
• DNA differs from RNA because it contains the sugar deoxyribose instead of ribose, it has the base uracil instead of thymine, and it is double-stranded rather than single stranded.
• Nucleic acids are long polymers of repeating subunits called nucleotides.
• Each nucleotide consists of three components: a pentose sugar, a phosphate group, and a nitrogenous base.
• When two nucleotides are joined by a condensation reaction, the phosphate group of one nucleotide binds to the nitrogenous base of the second nucleotide, forming a phosphodiester bond.
• A polynucleotide chain has a phosphate group at the 3´ end and a hydroxyl group at the 5´ end.
• During protein synthesis, the sequence of bases in RNA controls the sequence of bases in DNA which, in turn, controls the sequence of amino acids in a polypeptide.
• In DNA, adenine always pairs with thymine and guanine always pairs with cytosine.
• DNA is used to store information needed to make all proteins required by an organism and can pass that information on to the next generation.
• In order to make a protein, information stored in RNA must be transcribed into molecules of DNA which directs the synthesis of proteins.
• DNA cloning is the production of genetically identical copies of DNA, cells, or organisms through some asexual means.
• DNA cloning can be done to produce many identical copies of the same gene-that is, for the purpose of gene cloning.
• The purpose of genetic cloning is to determine the difference in base sequence between normal gene and mutated gene.
• Genetic cloning is used to genetically modify organisms in a beneficial way.
• Recombinant DNA (rDNA) contains DNA from two or more different sources, such as a human cell and a bacterial cell.
• The CRISPR system is based on an endonuclease enzyme called Cas9, which is capable of identifying specific sequences of nucleotides in the genomic DNA of the invading virus and breaking both of the DNA strands, thus inactivating the virus.
• DNA amplified by PCR can be analyzed for various purposes.
• A process called gel electrophoresis, which separates DNA fragments according to their size, was then employed; the result of fragment sorting was a pattern of distinctive bands that identified the person.
• Mitochondrial DNA taken from modern living populations was used to decipher the evolutionary history of human populations.
• CRISPR was first discovered in prokaryotes, where it acts as a form of immune defense against invading viruses.
• When subjected to DNA fingerprinting, selected fragments of chromosomal DNA produce a series of bands on a gel.
• RT-PCR allows the creation of recombinant DNA molecules containing DNA copies of only the exons of genes.
• The most widely used method of genome editing is called CRISPR (clustered regularly interspaced short palindromic repeats).
• The CRISPR system can be used by researchers to target a specific sequence of nucleotides, in almost any organism, for editing.
• Cas9 identifies the specific nucleotides to be cut using a guide RNA molecule that complementary base-pairs to the genomic DNA sequence.
• To make rDNA, a technician needs a vector, from a Latin word vehere which means “to carry,” by which rDNA will be introduced into a host cell.
• DNA fingerprinting uses PCR to generate copies of specific regions of DNA, which are then analyzed for length variations.
• The combination of these two techniques is called reverse transcription PCR (RT-PCR).
• DNA taken from a corpse burned beyond recognition can be matched to that on the bristles of the person's toothbrush.
• If the genomic sequence of the target is known, a complementary RNA strand can be used by Cas9 to produce a break in the DNA.
• Like the human fingerprint, the DNA of each individual is different and can be used for identification.
• Genome editing, the targeting of specific sequences in the DNA for removal or replacement, is a relatively new advance in DNA technology.
• RT-PCR allows study of the structure and function of gene products.
• RT-PCR can be used to determine relative levels of gene expression in cells.
• Analysis of DNA following PCR has undergone improvements over the years.